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Rice straw (RS) has been burned in open fields in many countries, which is a growing environmental concern. Anaerobic digestion (AD) of RS is one of the sustainable alternatives to open burning of RS for converting the biomass into methane, carbon dioxide, and digestate for use as agricultural manure. The present study evaluates the RS generation, use patterns, and greenhouse gas emissions from open field burning and the AD of RS. Results indicate the AD of RS offers greater environmental benefits than that by RS open field burning. As a result of the open burning of RS in India emitted 592032.52 kg of CO

The vermifiltration (VF) technology has gained significant attention as a green alternative for remediating domestic and industrial wastewater over the last few decades. Of late, the implementation of various modifications to the orthodox VF technology, including tweaks in the design and operation of the vermifilters, has been portrayed in the available literature. However, owing to the scatteredness of the available information, the knowledge regarding the execution of the modified vermifilters is still inadequate. Hence, an effort has been made to comprehensively overview the innovative strategies and techniques adopted to improve the organic and nutrient removal potential of the VFs from wastewater. In addition, future perspectives have been recognized to design more efficient and sustainable VFs. This review explores more of such novel tactics to improve the performance of the VF technology regarding organic and nutrient removal from wastewater. PRACTITIONER POINTS: Innovative strategies and techniques implemented to VF technology were comprehensively overviewed. Design modification and advantages of each innovation were highlighted. The pollutant removal performance of every modification was emphasized. Modified vermifilters were better than the conventional vermifilters in terms of organic and nutrient removal from the wastewater.

The Feng-Sang River is a metropolitan river in Kaohsiung City, Taiwan. In this study, Feng-Sang River sediments were analyzed to investigate the distributions and sources of polycyclic aromatic hydrocarbons (PAHs). The Sediment Quality Guidelines (SQGs), potentially carcinogenic PAHs (TEQ

The subject of emerging contaminants has attracted wide attention from researchers and society world over due to their emerging as well as potential adverse impacts on the environment. Many attempts have been made to shed light on the importance of the release of these contaminants into various environments and further urge policymakers to take required measures. Nevertheless, the effective long-term strategy for addressing this issue is latent in the modification of current technologies of wastewater/water treatment plants and integrating them into a holistic and circular water management system. The research on the new technologies of water treatment must be realigned to consider the real conditions and meet certain requirements set according to technical and environmental perspectives.

In the current study, sequential nitrification and anoxic experiments in synthetic municipal wastewater were exposed to 0.5 to 100 mg/L of chlortetracycline for 24 h to evaluate acute impact on the nitrification, and denitrification processes of biological treatment. Both processes were significantly (p0.05) inhibited at50 mg/L of chlortetracycline, and the results revealed that nitrification was adversely affected by chlortetracycline compared with the anoxic process. In nitrification, chemical oxygen removal (COD) and ammonia oxidation kinetics were 50% inhibited at 10 mg chlortetracycline/L, and nitrite oxidation kinetics at 0.5 mg chlortetracycline/L. Likewise, in the anoxic process, 14 and 10 mg/L of chlortetracycline inhibited 50% of COD removal and nitrate reduction kinetics, respectively. In nitrification and denitrification, 90% of chlortetracycline was removed by adsorbing onto sludge suspended solids. In addition, a higher chlortetracycline concentration in anoxic effluent, compared with aerobic effluents, indicated a dissimilarity in the composition of sludge solids, pH, and biomass production for both processes.

The goals of this study were to assess the effectiveness of (1) enhancing octachlorinated dibenzo-p-dioxin (OCDD) biodegradation under aerobic conditions by Pseudomonas mendocina NSYSU (P. Mendocina NSYSU) with the addition of lecithin, and (2) inducing OCDD ring-cleavage genes by pentachlorophenol (PCP) and OCDD addition. P. Mendocina NSYSU could biodegrade OCDD via aerobic cometabolism and lecithin was used as a primary substrate. Approximately 74 and 67% of OCDD biodegradation was observed after 60 days of incubation with lecithin and glucose supplement, respectively. Lecithin was also used as the solubilization additive resulting in OCDD solubilization and enhanced bioavailability of OCDD to P. Mendocina NSYSU. Two intradiol and extradiol ring-cleavage dioxygenase genes (Pmen_0474 and Pmen_2526) were identified from gene analyses. Gene concentration was significantly enhanced after the inducement by PCP and OCDD. Higher gene inducement efficiency was obtained using PCP as the inducer, and Pmen_2526 played a more important role in OCDD biodegradation.

Oleaginous yeast Trichosporon oleaginosus was studied for lipid production using municipal sludge with or without fortification of crude glycerol in a 15-L fermenter. The maximum lipid content (concentration) was 32.0% w/w (9.35 g/L), 33.6% (10.13 g/L), 33.3% (9.13 g/L), and 33.1% (9.03 g/L) w/w with the addition of 25, 50, 100, and 150 g/L glycerol, respectively. Glycerol concentration had little effect on lipid accumulation. However, glycerol concentration substantially affected increase of biomass concentration and cell count. The suitable glycerol concentration was approximately 40 g/L for Trichosporon oleaginosus growing in sludge medium with initial suspended solids (SS) concentration 30 g/L. Addition of nitrogen to sludge-glycerol medium enhanced lipid and biomass concentration. The energy conversion efficiency was 1.78, 1.55, and 1.71 with no nitrogen added, with addition of 1 g/L urea, and 3.7 g/L peptone, respectively. The biodiesel production cost was estimated nearly 0.75 US$/L.

The goal of this study was to establish a modeling tool for river water quality with a direct linkage to the water quality index (WQI5) calculation and the river water quality model, the Water Quality Analysis Simulation Program (WASP), for pollutant transport modeling. The integrated WASP and WQI5 tool was field-tested to assess pollutant loadings and their impacts on river environment. Suspended solid (SS) and electric conductivity (EC) correlation equations and the WQI5 calculation tool were included in the water quality model and direct WQI5 calculation. The SS concentration, which was influenced by river flows, had crucial effects on river water quality and WQI5 values. EC value was controlled by dissolution of soil minerals, which was affected by the watershed drainage area and surface runoff. The integrated system could establish a direct correlation for river water quality, river flow, and WQI5.

This study evaluates the technoeconomic feasibility of using hybrid advanced oxidation technologies (AOTs) for the removal of chlortetracycline (CTC) in wastewater treatment plant (WWTP). E...

Along with iron and steel production, large amount of slag is generated. Proper management on the iron- and steelmaking slag is highly demanded due to the high cost of direct disposal of the slag to landfill, which is the most adopted management approach. In this article, the potential application of iron- and steelmaking slag has been reviewed, which included the slag utilization in construction as cement and sand, in water, soil, and gas treatment, as well as in value material recovery. In addition, the challenge and required effort to be made in iron- and steelmaking slag management have been discussed.

Northeast India is rich in biodiversity; however, in recent decades due to increase in population and demand for economic development, this region has encountered massive changes in its lan...

There is a need of information on soil organic carbon data for global environmental management and food security. However, the difficulty lies in obtaining soil carbon data, especially in fragile mountainous regions like Northeast India which is complex in nature and difficult to access. The present study aims to model the distribution of soil carbon stock using digital mapping approach, to predict and generate continuous spatially explicit soil carbon map in Northeast India. Firstly, negative exponential depth function has been used to fit the vertical distribution of soil carbon data, and then Random Forest model has been trained and tuned to predict the parameters of the exponential function using climate data and satellite images. The obtained parameters were finally interpolated using ordinary Kriging method and spatial distribution map across the study area has been generated. Results indicate that the negative exponential function fits the data accurately with 94% of data having R2 > 0.7. Land use and topographic factors particularly elevation was found to have the most influence on SOC distribution in Northeast India. The findings from this study indicate good results for the application of this technique to predict and monitor soil carbon of the study area as a function of topographic factors and changes in land use and climate variables. The obtained results can also be connected to global carbon models to improve the understanding of carbon dynamics.

Nano zero-valent iron particles (nZVI) supported on granular activated carbon (GAC) (nZVI/GAC) were synthesized and its feasibility was explored for the treatment of pyridine-bearing wastewater. nZVI/GAC was synthesized by the borohydride reduction method under ethanol atmosphere. The synthesized nZVI/GAC was characterized by scanning electron microscopy (SEM), X-ray diffraction, Fourier transform infrared spectroscopy, and N2 adsorption–desorption study. Results indicated that the nZVI was well dispersed on the surface of GAC. The presence of support material apparently decreased the extent of aggregation and size of the nZVI and thus, facilitated in increasing the pyridine removal efficiency. Batch studies were carried out in order to evaluate the effect of operating parameters such as pH (2 ≤ pH ≤ 9), dose (m) (5 ≤ m ≤ 15 g/l), initial concentration (Co) (50 ≤ Co ≤ 1000 mg/l), and temperature (T) (288 ≤ T ≤ 318 K). At optimum condition, maximum removal of pyridine was found to be ~86% at m = 15...

Owing to hydrophobic nature, carbon nanotubes (CNTs) are resistant toward microbial degradation and they may be accumulated by soil/sediment dwellers. Bioaccumulated CNTs may enter the food chain and it may be a concern for human health. Laboratory studies have confirmed CNT bioaccumulation by both plants and animals; however, no report is available on CNT bioaccumulation by any organism present in the real CNT contaminated site. Thus, the present review summarizes environmental and other commercial applications of CNTs, their possible release, environmental behavior, and recent developments in environmental monitoring.

A hybrid upflow anaerobic sludge blanket (UASB)-moving bed biofilm (MBB) and rope bed biofilm (RBB) reactor was designed for treatment of sewage. Possibility of enhancing granulation in an UASB reactor using moving media to improve sludge retention was explored while treating low-strength wastewater. The presence of moving media in the top portion of the UASB reactor allowed a high solid retention time even at very short hydraulic retention times and helped in maintaining selection pressure in the sludge bed to promote formation of different sized sludge granules with an average settling velocity of 67 m/h. These granules were also found to contain plenty of extracellular polymeric substance (EPS) such as 58 mg of polysaccharides (PS) per gram of volatile suspended solids (VSS) and protein (PN) content of 37 mg/g VSS. Enriched sludge of nitrogen-removing bacteria forming a porous biofilm on the media in RBB was also observed in a concentration of around 894 g/m2. The nitrogen removing sludge also had a high EPS content of around 22 mg PS/g VSS and 28 mg PN/g VSS. This hybrid UASB-MBB-RBB reactor with enhanced anaerobic granular sludge treating both carbonaceous and nitrogenous matter may be a sustainable solution for decentralized sewage treatment.

This review summarizes the effect of high- and low-temperature thermal pretreatment (TPT) on sludge dewaterability, anaerobic digestion (AD), and biogas production efficiencies. The AD of the TPT sludge has demonstrated the following observations: reduced sludge retention time, increased biogas generation, higher organics degradation, improved dewaterability, and lower digester volume than the conventional AD of sludge. Energy balance of the TPT process was energetically self-sustainable and produced surplus energy at solids concentration greater than 3%. Net energy and energy ratio of TPT and AD revealed that net energy and energy ratio are increased with increase in total solids concentration.

The effect of chemical additives in combination with ultrasonication (US) was evaluated for the decolorization of simulated synthetic textile wastewaters containing Reactive Black 5 (RB5), Congo Red (CR), and Disperse Blue 3 (DB3). Maximum decolorization of 93% was achieved for the wastewater containing RB5 (50 mg L⁻¹) at 8 h sonication time and US power density of 1 W mL⁻¹. Persulfate (PS) assisted US was appeared to be better over the sodium sulfate (SS)-assisted US, giving 87.51% decolorization efficiency for the textile wastewater containing all the three dyes together (200 mg L⁻¹) at a PS dosage of 1500 mg L⁻¹ and the sonication time of 120 min. The rate of sonolytic decolorization followed first-order kinetics for the textile wastewater containing RB5 and CR. The results of this study indicate that, with an increase in the sonication time, the decolorization efficiency increases for the textile wastewater containing RB5 and CR, but decreases for that containing DB3.

Emerging contaminants (ECs) are compounds that recently have been shown to occur widely in the environment and identified as being a potential environmental or public health risk, but yet adequate data do not exist to determine their risk. This review article focuses on ECs including pharmaceuticals, personal care products, surfactants, plasticizers, fire retardants, pesticides and nanomaterials. Their source, fate and transport in landfill leachate and adjacent environments have been discussed. Furthermore, state-of-the-art control and treatment techniques for ECs in landfill leachate have been presented. Sustainable management efforts for screening and control of ECs have been discussed. Molecular biology techniques to enumerate microbes capable of degrading ECs in landfills and their leachate are introduced. The article also presents future perspectives on the management of ECs in landfill leachate.

The authors discuss occurrence of heterotrophic microbes, specifically bacteria, yeast, and molds, in biodiesel production is well discussed. Besides, these oleaginous microorganisms are reported to accumulate triacylglycerols (TAGs) that contain long-chain fatty acids. Most of the evidence suggests that TAGs accumulated are suitable for biodiesel production. Lipid accumulation (de novo or ex novo) required a set of enzymes and expression of various genes that are under complex regulatory system. The authors take a step in this direction and provides a summary of the actual knowledge on heterotrophic oleaginous species, their fatty acids, TAGs, and sterol biosynthesis with a biochemical and genetic approaches to better understand their regulation. Likewise, the impact of abiotic factors that can contribute to higher lipid accumulation is summarized. This review also highlights various issues concerning genetic engineering that may contribute to an advanced path forward for microbial feedstock-based biodiesel.

Summary The objective of this study was to evaluate the effectiveness and mechanisms of natural attenuation (NA) on the remediation of petroleum-hydrocarbon contaminated groundwater caused by gasoline and diesel fuel leakage. During the effectiveness investigation, site groundwater samples were collected and analyzed for the variations in geochemical indicators, microbial diversity, dominant bacteria, biodegradation rates, biodegradation capacity, and the trend of contaminant degradation. Results show that the total BTEX (benzene, toluene, ethylbenzene, and xylenes) concentrations dropped from 9.5 mg/L at the source zone to 0.06 mg/L at a 120-m downgradient line. The calculated BTEX biodegradation capacity (20 mg/L) was much higher than the BTEX concentrations (9.5 mg/L) within the most contaminated area. This indicates that the spilled BTEX could be completely biodegraded through different intrinsic microbial processes using available electron acceptors. Results from polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and nucleotide sequence analyses reveal that the petroleum-hydrocarbon plume caused the bacterial variation in microbial communities, and more than 27 different petroleum-hydrocarbon degrading bacteria were observed in site groundwater indicating that BTEX could be biodegraded by the intrinsic bacterial consortium. Results also imply that the occurrence of intrinsic biodegradation was the major cause of the limited spreading of the BETX plume and reduction of contaminant concentrations. Results from Mann–Kendall test reveal that BTEX concentrations were decreasing in all monitor wells, and the BTEX first-order NA rate was 5.4 × 10−4 1/d along the transport path. The observed NA processes within the plume included the following: (1) depletion of electron acceptors (e.g., dissolved oxygen, nitrate, sulfate), (2) production of the degradation products (e.g., ferrous iron, sulfide, methane, CO2), (3) decreased BTEX concentrations along the groundwater flow direction, (4) a decreased trend of BTEX concentrations in monitor wells, (5) increased alkalinity, (6) increased microbial populations, (7) deceased pH in the spill source area, and (8) preferential removal of certain BTEX components along the transport path. Results indicate that NA can effectively contain the plume, and intrinsic biodegradation mechanisms were the major causes for contaminant removal. Results will be useful in applying NA as an alternative option for the management of petroleum-hydrocarbon contaminated sites.

Petroleum hydrocarbon–contaminated soil and groundwater is a worldwide environmental problem, which results in environmental hazard and human health risk problems. Because petroleum is a complex composition mixture rather than a single compound, health risk assessment for a petroleum hydrocarbon–contaminated site is a complicated process. In this study, a modified total petroleum hydrocarbons (TPH) fraction method was applied to determine the health risk level for each TPH fraction. The concentrations and toxicity data of total of 13 TPH fraction categories were evaluated and used for risk calculation. Results show that up to 1,772 mg/kg of TPH concentration was observed in soils collected from the studied site. Results indicate that benzene was the most concerning chemical that appeared in TPH. The calculated cancer risk for benzene was 4.48×10−7, which was lower than the minimum total cancer risk level (1×10−6). The calculated hazard quotient for the noncarcinogenic compounds was slightly highe...

Summary The Kaoping River Basin is the largest and most extensively used watershed in Taiwan. In the upper catchment, the non-point source (NPS) pollutants including suspended solid (SS) and ammonia nitrogen (NH 3 –N) are two major water pollutants causing the deterioration of Kaoping River water quality. Because SS is one of the four parameters involving in the River Pollution Index (RPI) calculation, it needs to be carefully evaluated to obtain the representative water quality index. The main objective of this study was to develop a water quality modeling system to obtain representative SS and RPI values for water quality evaluation. In this study, a direct linkage between the RPI calculation and a water quality model [Water Quality Analysis Simulation Program (WASP)] has been developed. Correlation equations between Kaoping River flow rates and SS concentrations were developed using the field data collected during the high and low flows of the Kaoping River. Investigation results show that the SS concentrations were highly correlated with the flow rates. The obtained SS equation and RPI calculation package were embedded into the WASP model to improve interactive transfers of required data for water quality modeling and RPI calculation. Results indicate that SS played an important role in RPI calculation and SS was a critical factor during the RPI calculation especially for the upper catchment in the wet seasons. This was due to the fact that the soil erosion caused the increase in the SS concentrations after storms. In the wet seasons, higher river flow rates caused the discharges of NPS pollutants (NH 3 –N and SS) into the upper sections of the river. Results demonstrate that the integral approach could develop a direct linkage among river flow rate, water quality, and pollution index. The introduction of the integrated system showed a significant advance in water quality evaluation and river management strategy development.

Thirteen extracellular polymeric substances (EPS) producing bacterial strains were cultivated (as mixed culture) in the sterilized sludge (suspended solids of 25 g/L) and the batch fermentation was carried out. Mixed culture revealed a high specific growth rate of 0.35/hr. The EPS production rate was higher up to 24 hours, which gradually decreased with further incubation. The kinetic estimates demonstrated growth-associated EPS production. Broth EPS revealed higher flocculation activity when combined with different cations (Ca 2+ , Mg 2+ , Fe 3+ , and Al 3+ ) in river water (≥90%), municipal wastewater (≥90%), and brewery wastewater (≥80%), respectively. A low dose (5 to 40 mg/L) of trivalent cations was required to achieve higher flocculation compared to the divalent cations (50 to 250 mg/L). Flocculation performance of EPS was comparable to Magnafloc-155 (chemical polymer) and, hence, it could be used as a flocculant.

Nature’s ability of programming the synthesis of different metallic nanoparticles has paved way to a new green era in an unforeseen fashion. However, there is a timely need to delve into the practical implications and challenges of this green science. The working principles of green synthesis need a critical analysis for the factual evaluation of different green domains endorsed in it. The inclusion of nongreen elements, such as heat energy and organic solvents, seems to alter the original scope of green synthesis. Moreover, green chemistry principles, green nanotechnology, and green synthesis should be reconsidered within the zone of their interception for conclusive evidence. A new concept, “all green,” is foreseen in this article for a greener nanoscience and analyzed for its practical feasibility.

Ozonation pre-treatment was investigated for the enhancement of sludge solids and organic matter solubilization and simultaneous degradation of bisphenol A (BPA), an endocrine disruptor compound from wastewater sludge (WWS). The ultrafast method (15 s per sample) used for the analysis of BPA in WWS is based on Laser Diode Thermal Desorption/Atmospheric Pressure Chemical Ionization coupled to tandem Mass Spectrometry. The statistical methods used for optimization studies comprised the response surface method with fractional factorial designs and central composite designs. The ozonation pre-treatment process was carried out with four independent variables, namely WWS solids concentration (15-35 g l(-1)), pH (5-7), ozone dose (5-25 mg g(-1) SS) and ozonation time (10-30 min). It was observed that among all the variables studied, ozone dose had more significantly (probability (p)0.001) affected the efficiency of the ozonation pre-treatment by increasing sludge solids (suspended solids (SS) and volatile solids) solubilization and organic matter (soluble chemical oxygen demand and soluble organic carbon) increment and BPA degradation from WWS. During the optimization process, it was found that higher BPA degradation (100%) could be obtained with 24 g l(-1) SS, 6.23 pH with an ozone dose of 26.14 mg g(-1) SS for 16.47 min ozonation time. The higher ozone dose used in this study was observed to be cost effective on the basis of solids and organic matter solubilization and degradation of BPA.

This paper presents numerical and parameter estimation models for the analysis of virus transport and the identification of transport parameters in the unsaturated zone. The numerical model couples a mass conservative fully implicit finite difference model simulating moisture flow in the unsaturated zone with the hybrid finite volume model for virus transport. The accuracy of the numerical scheme is tested for both advection- and dispersion-dominated transport. The comparison of the numerical model with the analytical solution indicates that the numerical model’s predictions are in excellent agreement with the analytical predictions. The parameter estimation is formulated as a nonlinear least-squares minimization problem in which the parameters are estimated by minimizing the deviations between the model-predicted and experimentally observed virus concentrations. A parameter estimation procedure is developed by coupling the numerical model simulating one-dimensional virus transport in the unsatura...

Summary The objective of this study was to evaluate the variations in assimilable organic carbon (AOC) and microbial diversities in an advanced water treatment plant. The efficiency of biofiltration on AOC removal using anthracite and granular activated carbon (GAC) as the media was also evaluated through a pilot-scale column experiment. Effects of hydrological factors (seasonal effects and river flow) on AOC concentrations in raw water samples and hydraulic retention time (HRT) of biofiltration on AOC treatment were also evaluated. Results show that AOC concentrations in raw water and clear water of the plant were about 138 and 27 μg acetate-C/L, respectively. Higher AOC concentrations were observed in wet seasons probably due to the resuspension of organic-contained sediments and discharges of non-point source (NPS) pollutants from the upper catchment. This reveals that seasonal effect played an important role in the variations in influent AOC concentrations. Approximately 82% and 70% of AOC removal efficiencies were observed in GAC and anthracite columns, respectively. Results from column experiment reveal that the applied treatment processes in the plant and biofiltration system were able to remove AOC effectively. Microbial colonization on GAC and anthracite were detected via the observation of scanning electron microscopic (SEM) images. Results of polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and nucleotide sequence analysis reveal significant decrease in microbial diversities after the ozonation process. Higher HRT caused higher microbial contact time, and thus, more microbial colonies and higher microbial diversity were observed in the latter part of the biofilters. Some of the dominant microbial species in the biofiltration columns belonged to the beta-proteobacterium, which might contribute to the AOC degradation. Results of this study provide us insight into the variations in AOC and microbial diversity in the advanced water treatment processes.

In this study, sensitivity analysis was performed to evaluate the effectiveness of input parameters on the calculated risks at a petroleum-hydrocarbon contaminated site. Under a risk-based correcti...

In this study, a practicable and effective analytical method based on solid-phase-extraction and reversed-phase liquid chromatography with fluorescence detection (SPE-LC-FLD) was developed and partially validated for routine analysis of eight FQs in wastewater at the trace level. Different SPE materials, pH conditions and eluents were modified to find an economic and effective SPE conditions. In our work, it is the first time that well-known commercially available SPE sorbent are compared to ‘generic’ cheap SPE sorbent. Aqueous samples (pH 2–3) were extracted using Anpel™ MEP cartridges where they were subsequently eluted by 6 mL of 2% formic acid in MeOH. The aqueous extracts were analysed by gradient elution LC-FLD, whose initial mobile phase was composed of ACN and 10 mmol L−1 tetrabutyl ammonium bromide (4/96, v/v, pH 3). The LODs and LOQs of the wastewater were as low as 0.32–2.12 ng L−1 and 1.07–7.07 ng L−1, respectively. The precisions of the overall method (RSD, n = 3) using wastewater were below ...

All degradable organic materials are decomposed by microorganisms, and considerable amounts of nitrogen end up as gaseous metabolites. No matter what procedure is chosen for getting rid of organic wastes (wastewater treatment, landfiling, and composting), microbial communities will always be involved in the decomposition process, and hence, emissions of greenhouse gases, including nitrous oxide ( N2 O ) , are inevitable with these processes. N2 O is an influential greenhouse gas, vital on climate change, and also is a depleting substance of stratospheric ozone. Any instantaneous or eventual N2 O emissions during wastewater treatment, biosolids landfilling, and composting must be measured as anthropogenic intrusion of global N2 O cycle, and thus plays a decisive role in ozone depletion. This paper reviews the current available literatures concerning N2 O emissions from wastewater treatment facilities, biosolids landfilling, and composting. The outcome of this survey portrays that each process can release a...

The Kaoping River Basin, located in southern Taiwan, flows through approximately 171 km and drains toward the South Taiwan Strait. It is the largest and the most intensively used river basin in Taiwan. However, due to the concentrated rainfall in the wet season, short rivers and rapid flows, poor flow conditions, uneven time distribution of flows, and rapid rise of flow peak cause the unevenly distributed water resource in this region. Based on the results from the water resource analysis and water demand evaluation, a shortage of water supply in the basin would occur in 5 years. Sustainable water resource management strategies have been proposed to effectively utilize the limited water resource in the basin. The proposed strategies include construction of water collection gallery system, installation of riverbank infiltration system, installation of groundwater recharge and extraction systems, recycling the effluent from the secondary wastewater-treatment plant, and replacement of old water supply pipes....

Emerging contaminants (ECs) have been wildly distributed in the environment and attracted increasing attention over the past decades. In this paper, the contaminants including pharmaceuticals and personal care products, surfactants, and their degradation products, plasticizers, pesticides, and fire retardants are comprehensively reviewed. Their main categories, properties, followed by their occurrences and behavior (fate and transport) in natural and engineered systems are discussed. The fate of the nanomaterial in different environmental compartments as well as their effects on human health and other fauna are also presented in this paper. Furthermore, the emerging molecular biology techniques to enumerate microbes capable of degrading ECs are introduced. The study has clearly showed the presence of complex mixtures of ECs, having various origins, and raised concern about their potential interactive effects in the environment.

Total solids (TS) concentrations ranging from 15 to 66 g L(-1) of starch industry wastewater (SIW) were tested as raw material for the production of Bacillus thuringiensis var. kurstaki HD-1 (Btk) biopesticide in shake flasks and a 15 L bench-scale fermenter. Shake flask studies revealed a higher delta-endotoxin concentration of Btk at 30 g L(-1) TS concentration and 2.5% (v v(-1)) volume of pre-culture. The fermenter experiments conducted using SIW at 30 g L(-1) TS concentration under controlled conditions of temperature, pH and dissolved oxygen showed higher spore count, enzyme production (protease and amylase) and delta-endotoxin concentration as compared with those of SIW at 15 g L(-1) TS concentration. The entomotoxicity, at the end of fermentation, with SIW at 30 g L(-1) solids concentration (17.8 x 10(9) SBU L(-1), measured against spruce budworm) was considerably higher as compared with entomotoxicity at 15 g L(-1) solids concentration (15.3 x 10(9) SBU L(-1)) and semi-synthetic medium (11.7 x 10(9) SBU L(-1)). The pellet, comprising spores and delta-endotoxin complex obtained after centrifugation and followed by resuspension (in supernatant) in one-tenth of the original volume, of SIW at 30 g L(-1) solids concentration media registered the highest potential for application (to protect forests against spruce budworm) than other media in term of entomotoxicity.

Nanosilver has been used broadly in nanotechnology enhanced consumer products because of its strong antimicrobial properties. Silver nanoparticles (AgNPs) released from these products will likely enter wastewater collection and treatment systems. This research evaluated the role of sulfide and ligand strength in controlling nanosilver toxicity to nitrifying bacteria that are important in wastewater treatment. The nanosilver toxicity in the absence and presence of ligands (SO(4)(2-), S(2-), Cl(-), PO(4)(3-), and EDTA(-)) commonly present in wastewater was determined from the oxygen uptake rate measurements. Sulfide appeared to be the only ligand to effectively reduce nanosilver toxicity. By adding a small aliquot of sulfide that was stoichiometrically complexed with AgNPs, the nanosilver toxicity to nitrifying organisms was reduced by up to 80%. Scanning electron microscopy coupled with energy dispersive X-ray analysis indicated that AgNPs were highly reactive with sulfide to form new Ag(x)S(y) complexes or precipitates. These complexes were not oxidized after a prolonged period of aeration (18h). This information is useful for wastewater treatment design and operation to reduce nanosilver toxicity via sulfide complexation. While the biotic ligand model was successful in predicting the toxicity of Ag(+) ions, it could not accurately predict the toxicity of AgNPs. Nevertheless, it could be one of the many tools useful in predicting and controlling nanosilver toxicity to wastewater microorganisms.

Seventy-four bacterial isolates were recovered from 10 protein rich soil and water samples collected from Quebec City. On the basis of colony size, texture, and microscopic characteristics, the isolates were categorized into 33 types. Among these, five isolates showed good proteolytic activity (>5) , eight isolates showed moderate activity (between >3.0 and 2.0 and

Applications of nanomaterials in environmental protection have created conditions to improve environment and control pollution, which will bring breakthrough progress to environmental science and engineering. Using nanomaterials to solve environmental issues will become an inexorable trend in the future. Applications of nanomaterials in green chemistry, photocatalytic degradation of organic pollutants, remediation of polluted soils or water, pollutant sensing and detection, and so on, have been introduced. Besides, the potential risks of nanomaterials were also briefly discussed.

Sludges are inevitable products of wastewater treatment processes, which have to be managed efficiently to meet stringent laws and regulations being enforced day by day. Currently, there exist three major options for complete sludge management—control at source by process modification; improvement in handling, processing, and disposal, and reuse to produce value-added products. The source control and improvement in handling and disposal practices have been reviewed by various authors and it is actually sludge reprocessing to value-added products that holds the future key to sustainable management. Thus, the primary focus of this review is the value addition of sludge comprising recovery of different components and development of commercial products. The production of various value-added products, namely, soil amendments, construction aggregates, fuels, biotechnology products, biosorbents, and miscellaneous have been examined addressing the key issues of production method limitations, benefits, and possibl...

The occurrence of ciprofloxacin (CIP), sulfamethoxazole (SMX), and azithromycin (AZI) was evaluated in various aqueous streams of four municipal wastewater treatment plants (WWTPs) in the Midwestern United States. Aqueous phase grab samples were collected from different locations in the WWTPs at four different times of the year. The target compounds were extracted using solid phase extraction, separated with high-performance liquid chromatography, and identified/quantified using ultraviolet and fluorescence spectroscopy (CIP and SMX) or mass spectrometry (AZI). Aqueous phase concentrations for CIP and AZI were similar to literature values while SMX concentrations were generally higher than those reported in the literature. The average aqueous phase concentrations for CIP, AZI, and SMX in the raw wastewater were 1.44, 1.11, and 18.3 μg∕L , respectively, while the concentrations in the WWTP effluent were 0.59, 1.23, and 3.25 μg∕L , respectively. AZI concentration was consistently lower in the winter. While ...

Activated sludge from a full-scale pulp-paper industry wastewater treatment plant was used as a source of microorganisms to produce biodegradable plastics (polyhydroxyalkanoates) (PHA) at 25°C , pH 7 and at different initial sludge suspended solids (SS) concentration (5, 10, 15, and 20 g∕L ) in computer controlled fermentors. Acetate was used as sole carbon source at varying concentrations (5–20 g∕L) . The fresh sampled sewage sludge was found to contain PHA and the amount varied with the sampling date. The PHA productivity and concentration varied with intial sludge SS and acetate concentrations. Maximum accumulation of PHA ( 39.6% w∕w of dry sludge SS) was observed at 15 g∕L SS and 10 g∕L acetate concentration. The sludge biomass increased during the process, however, the net amount of the sludge residual solids after extraction of PHA was decreased to varying degrees depending on sludge SS and acetate concentration (5.5–36.9% w∕w) . Acetate concentration above 10 g∕L was found to be inhibitory for PHA ...

Filamentous and nonfilamentous microorganisms can cause bulking and foaming in wastewater sludge settling and dewatering. In this research, sludge degradation and bioflocculation was studied using pellet-forming filamentous fungi isolated from municipal wastewater sludge. To understand the role of filamentous fungi in sludge settling and dewatering, the isolated fungi was inoculated with both spores and pellets (beads) into sterilized and nonsterilized sludge having different suspended-solids concentrations. Biofloc formation, sludge settling, sludge degradation, change in pH of fungal-grown medium, zeta potential, and microscopic analysis of bioflocs were performed. The suspended-solids concentration was found to decrease over 5 d of incubation because of use and biodegradation by fungal biomass. The isolated fungal strain was well adapted to forming biofloc and to interacting with natural microbial flora and exhibited low capillary-suction time for sludge dewatering.

Emerging nanomaterials are of great concern to wastewater treatment utilities and the environment. The inhibitory effects of silver nanoparticles (Ag NPs) and other important Ag species on microbial growth were evaluated using extant respirometry and an automatic microtiter fluorescence assay. Using autotrophic nitrifying organisms from a well-controlled continuously operated bioreactor, Ag NPs (average size=14+/-6 nm), Ag(+) ions (AgNO(3)), and AgCl colloids (average size=0.25 microm), all at 1mg/L Ag, inhibited respiration by 86+/-3%, 42+/-7%, and 46+/-4%, respectively. Based on a prolonged microtiter assay, at about 0.5mg/L Ag, the inhibitions on the growth of Escherichia coli PHL628-gfp by Ag NPs, Ag(+) ions, and AgCl colloids were 55+/-8%, 100%, and 66+/-6%, respectively. Cell membrane integrity was not compromised under the treatment of test Ag species by using a LIVE/DEAD Baclight bacterial viability assay. However, electron micrographs demonstrated that Ag NPs attached to the microbial cells, probably causing cell wall pitting. The results suggest that nitrifying bacteria are especially susceptible to inhibition by Ag NPs, and the accumulation of Ag NPs could have detrimental effects on the microorganisms in wastewater treatment.

This study investigated the presence of chitinases in Bacillus thuringiensis ssp kurstaki HD-1 (Bt) fermented broths of wastewater sludge (non-hydrolyzed and hydrolyzed); starch industry wastewater and soyameal. Chitinase activity was absent in soyameal and present in others. Chitinase demonstrated peaks at pH 4.0 and temperatures 40 and 50 degrees C with higher activity between pH 4-5 and 10-11. The chitinase band on SDS-PAGE was found to be between 36 and 45 kDa for non-hydrolyzed (NH) and hydrolyzed sludge (TH) and starch industry wastewater. The chitinase profile during fermentation showed peaks at 15 and 30 h for non-hydrolyzed and hydrolyzed sludge and 15 and 24 h for starch industry wastewater. Chitinase retained 96-99 % activity after two weeks incubation at room temperature and pH 4. Bioassays with supplementation of Bt chitinases showed 1.2 fold increase in entomotoxicity of wastewater sludge and a small increase in starch industry wastewater. This study sheds light on production of Bt chitinases in alternative media which will have a long term effect on entomotoxicity of these formulations.

Wastewater sludge is a complex raw material that can support growth and protease production by Bacillus licheniformis. In this study, sludge was treated by different thermo-alkaline pre-treatment methods and subjected to Bacillus licheniformis fermentation in bench scale fermentors under controlled conditions. Thermo-alkaline treatment was found to be an effective pre-treatment process in order to enhance the proteolytic activity. Among the different pre-treated sludges tested, a mixture of raw and hydrolysed sludge caused an increase of 15% in the protease activity, as compared to the untreated sludge. The benefit of hydrolysis has been attributed to a better oxygen transfer due to decrease in media viscosity and to an increase in nutrient availability. Foam formation was a major concern during fermentation with hydrolysed sludge. The studies showed that addition of a chemical anti-foaming agent (polypropylene glycol) during fermentation to control foam could negatively influence the protease production by increasing the viscosity of sludge.

Particle size distribution studies were performed on raw, hydrolyzed, sterilized, and Bacillus thuringiensis (Bt) fermented wastewater sludge at different solids concentration (10–40 g L−1 ) . Correlations of particle size (PRS) were drawn with different parameters like sludge volume index (SVI), sedimentation velocity, viable spores, and entomotoxicity. The volume distribution of particle size showed a greater number of particles for hydrolyzed fermented wastewater sludge in the 0.2–12 μm region in comparison to nonhydrolyzed Bt fermented sludge where the PRS was restrained to a 0.5–10 μm region at a cumulative volume percent of 30 and 20%, respectively, irrespective of solids concentration. Similar trends were observed for surface distribution profiles. The entomotoxicity decreased and SVI increased with an increase in particle size. The sedimentation velocity was computed based on Stoke’s law and was lower for hydrolyzed sludge. The lower SVI and particle size of hydrolyzed fermented sludge are the req...

This paper reviews the current United States sewage sludge disinfection regulations and their associated practices; discusses the limitations of the practices; the criteria employed in evaluating a new (innovative or alternative) disinfection process, and notes both some processes recently evaluated and ones evaluated. The United States regulations are designed to protect human health by minimizing the contact of humans with pathogenic microorganisms. Two types of disinfection processes are employed. Processes like pasteurization are employed to reduce pathogens below their analytical detection limits, while processes like anaerobic digestion are combined with requirements for organic matter reduction and access restrictions. Issues with the present disinfection alternatives such as their only being concerned with the presence or absence of certain pathogens like enteric viruses or Ascaris sp. are discussed and remedies suggested. Similarly, several of the current options for measuring vector attractivene...

Wastewater (WW) for irrigation and application of biosolids in soil is becoming important as it is going to become very common in the near future. By 2050, the world is going to have four billion people living in water-scarce countries, making it a norm of freshwater for the cities and WW for agriculture. Further, biosolids might still be used as green biofertilizers for soils, if they are improved from an ecological point of view. However, application of biosolids in soil is argued because of the amount of organic pollutants that compromise the dynamic equilibrium of the biological systems. Therefore, information on the concentration, behavior, and cycling of organic pollutants as well as their possible degradation pathways is needed to predict, prevent, and remediate these pollutants from different sources including WW and biosolids. Among the group of organic pollutants, emerging contaminants (ECs) enter into the soil with the irrigation water from treated effluents and fertilization by biosolids. Quantification of ECs from WW and biosolids is of main importance to predict the toxic effects of WW effluents and sludge. Moreover, their incorporation into vegetables through irrigation and their magnification through natural food webs have been proved and must be monitored. This review presents information on the different sources of emerging contaminants and linking with the ecological effects they produced by reacting in the environment during various applications of WW and biosolids in soil. The available methods for analysis and quantification of ECs in different matrices, such as WW and biosolids, are also presented. Fil: Mohapatra, D. P.. Université du Québec a Montreal; Canadá Fil: Cledón, Maximiliano. Université du Québec a Montreal; Canadá. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Brar, Satinder Kaur. Université du Québec a Montreal; Canadá Fil: Surampalli, R.. University of Nebraska; Estados Unidos

Nanomaterials (NMs) present some interesting properties that may be tailored; for this reason, they are being used in different fields, which leads to their entry into the environment, whether by normal use or intentional delivery. Once in water and sediments, they undergo different transformations that might be difficult to predict. NMs are also difficult to characterize because the methods for this are recently developed. Currently, the most plausible approach is to combine separation and measurement techniques; one of the most versatile integrations is field-flow fractionation with inductively coupled plasma mass spectrometry (ICP–MS) or ICP optical emission spectrometry. In the same way, toxicity assays must be adapted to these emerging contaminants because they behave neither as chemical compounds nor their bulk counterparts, which produces different results. Nevertheless, several adverse effects of NMs exposure on organisms have been reported, including DNA damage, mortality, oxidative stress, and growth reduction. However, the majority of these studies utilized acute laboratory exposure, whereas in a real ecosystem, organisms are more likely to experience chronic exposure conditions to numerous NMs and a biomagnification effect should be expected through the trophic chain. Despite the lack of sufficient literature, the present review attempts to link various compartmentalization aspects of NMs, their physical properties, and their toxicity in surface water and sediments. Fil: Maiti, Sampa. Université du Québec; Canadá Fil: Fournier, Isabelle. Université du Québec; Canadá Fil: Brar, Satinder Kaur. Université du Québec; Canadá Fil: Cledón, Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Surampalli, R. Y.. Universidad de Nebraska - Lincoln; Estados Unidos

Industrial revolution has led to the introduction of innumerable contaminants into the environment via industrial, agricultural, and household applications. In particular, engineered nanoparticles (ENPs), which are emerging in the natural environment and being transported in the environment, may have a significant effect on ecosystems, even though they may only be present at low concentrations. Nanotechnology is going to play a major role which will be responsible for the release of ENPs in the environmental matrices and thus has led to increased focus on environmental research for the betterment of human society. Despite widespread applications of ENPs, in recent years, their hazardous effects on the air, water, soil, and sediments have been studied, which directly impact human health. Hence, to evaluate their persistence and understand the mechanisms that affect their fate, it is necessary to obtain realistic impact due to significant concentration of ENPs. The application of analytical techniqu...